A beginner's guide to chicken design

Provided by New Zealand Lifestyle Block, incorporating Growing Today, magazine.

While it can take decades to develop a new breed of chicken, you can use basic principles of breeding to improve aspects of your cross-bred birds, as Sue Clarke explains.

Assuming that most of you probably have flocks made up of "Heinz 57" (cross-bred) birds, you may have wondered if it's possible to breed birds which are suitable for laying eggs or for eating, or birds that are dual-purpose, which means they're a bit of both.

We're assuming that most of you will have roosters, so breeding your own birds is not a problem.

Chicken breeding for commercial purposes is a very specialised industry. Over the past 80 years the hybrid chicken has become a highly productive cross breed that can maximise either egg numbers and quality, or growth rate and feed efficiency.

There are several major poultry breeding companies worldwide, but in New Zealand the grandparents of commercial layer and meat chickens are imported from North America as hatching (fertile) eggs. They are the forebears of the Shaver Brown and the Hyline Brown egg layers, which produce the over three million commercial laying hens in New Zealand, and the Ross and Cobb meat chickens, which produce over 80 million meat (broiler) chickens per year.

How to create a super layer

The home breeder won't ever reproduce birds as good as the commercial hybrids, which have been developed using huge genetic selection programmes, at great expense, over many years.

However, this genetic material is available, so you can start with a commercial layer hen or meat chicken. It will be well ahead of the performance of the purebred breeds available in New Zealand.

I hasten to add, you will never create a bird as good as these hybrids because they are the end result of a multi-strain cross, and never breed true to type. However, using a commercial layer hen like a Hyline or a Shaver Brown and mating it to a light breed rooster like a Leghorn or a Minorca, will give you some pullet chicks which will probably lay more than the average 'barnyard bred' layer.

Some of the pure or fancy heritage breeds have been bred for looks rather than egg production, so you will need to concentrate on only breeding from the birds that exhibit the laying ability you want or egg production will gradually diminish in subsequent generations.

An egg layer must have the following traits:

• She should mature early, that is become sexually mature and lay eggs from around 20 weeks of age, if not earlier.
• Egg production should persist as long as possible, so she should not go broody, or if so then very rarely.
• Her clutch size - that is, eggs laid on consecutive days - should be as many as possible, preferably 30 or more.
• Her egg's shells should be strong, well-shaped and size should increase from pullet eggs to size 7's rapidly, but not get too big.
• The internal egg quality should be as perfect as possible - no blood or meat spots - with a thick albumen and a yolk that doesn't easily break.

All these traits are heritable and the more you select for these, the stronger they become. Choose a rooster whose mother/sisters have all the best qualities you want and put them over your better-performing hens.

How to create a good roast

When you select for the qualities you want in a meat bird, they tend to be the opposite of the qualities you find in a layer: when you select for meat, you lose egg numbers.

The qualities required for a good meat bird are:

• Fast growth rate from day one.
• A strong, sturdy build to carry maximum muscle on breast and legs.
• Preferably white feathered, so you don't see the coloured stubs in the plucked bird's pin feathers.
• White-skinned, preferableto yellow to some people (choose your preference)
• Good feed conversion to meat

Feed conversion efficiency, by which the least food is converted into muscle, is essential. In a layer, the feed conversion is referred to as feed per egg, or more usually weight of feed to weight of eggs. If you select for a fast-growing, feed-efficient bird, you are selecting against fertility and reproduction, because big, meaty birds don't lay as many eggs as specially bred layers - in fact, only about half the number.

Breeding choices

A dual-purpose bird will grow and produce some meat and lay eggs, but not as good as a bird with just the one agenda.

If you want to improve the birds you have then decide which you want more - eggs or meat? To have both makes it very hard to select which birds to breed.

If you are starting off with some purebred chickens, perhaps heavy breeds such as the Light Sussex, Rhode Island Red (RIR) or Orpington, or light breeds like Leghorn or Minorca, it pays to know if your birds are giving you enough of what you want. This makes record-keeping for each bird very important.

For example, the Light Sussex is classed as dual-purpose, and traditionally it would have been a good egg layer and a meaty bird, but nowadays some strains are poor layers. It's a similar problem with some Leghorns, especially some of the more unusual colours.

Eggs

To really check whether you are making progress you should record your egg production daily. Memory of egg production cannot be relied upon and it is a bit like the fish that got away - it grows bigger with time!

Breed only from the hens which exhibit the best egg production traits, and eat the eggs of the hens which are not so good. You will need to segregate the best hens to check their performance.

An old method of doing this was to use trap nests to record individual hens - these locked the hen in after she entered the nest, to be released by the breeder after she had laid her egg. Each egg could then be recorded with the date and her ID, and that of whichever rooster she was mated to. However, you'd need to be checking it often, so the hen wasn't trapped for any period of time.

Meat

If you want to improve the meatiness of your birds, select the rooster for breeding which grows the fastest and has good, meaty legs and breast, then mate him to your plumpest hens. If you want to inject a bit of growth into your birds, try getting a commercial meat rooster and mating him across breeds like the Light Sussex or Dorking.

This article was provided by NZ Lifestyle Block, incorporating Growing Today magazine.
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